Drugs, such as anesthetics, are sometimes mixed and administered to patients at the point of care. For example, in operating rooms, anesthesiologists often transfer drugs from an original container to a second container, e.g. a syringe, for administration to patients and they can also dilute a drug from a concentrated form to a less concentrated form for administration to a particular patient. Regulations and standards of good practice require the prepared drug be labeled with information such as the drug name, its concentration, who prepared it, and the date/time of its creation and expiration. The labels can be color coded based on a standard color coding scheme promulgated by the American Society of Anesthesiologists (ASA) to help physicians quickly identify the type of drug that is in a container, for example, a syringe, during busy or emergency situations.
Other materials including, for example, stock chemicals in a medical laboratory or hazardous waste being transported or stored also require labels in which standard colors and/or symbols have specific meanings.